    main window to prevent UI interactivity and place user focus on the modal window.
    Parameters:
     - child:  The message to display in the modal (a string or a hiccup vector or function returning a hiccup vector)"
-  [& {:keys [child wrap-nicely? backdrop-color backdrop-opacity class style attr]
+  [& {:keys [child wrap-nicely? backdrop-color backdrop-opacity backdrop-on-click class style attr]
       :or   {wrap-nicely? true backdrop-color "black" backdrop-opacity 0.6}
       :as   args}]
   {:pre [(validate-args-macro modal-panel-args-desc args "modal-panel")]}

   {:name :wrap-nicely?     :required false :default true    :type "boolean"                                        :description [:span "if true, wrap " [:code ":child"] " in a white, rounded panel"]}
   {:name :backdrop-color   :required false :default "black" :type "string"          :validate-fn string?           :description "CSS color of backdrop"}
   {:name :backdrop-opacity :required false :default 0.6     :type "double | string" :validate-fn number-or-string? :description [:span "opacity of backdrop from:" [:br] "0.0 (transparent) to 1.0 (opaque)"]}
   {:name :class            :required false                  :type "string"          :validate-fn string?           :description "CSS class names, space separated"}
   {:name :style            :required false                  :type "CSS style map"   :validate-fn css-style?        :description "CSS styles to add or override"}
   {:name :attr             :required false                  :type "HTML attr map"   :validate-fn html-attr?        :description [:span "HTML attributes, like " [:code ":on-mouse-move"] [:br] "No " [:code ":class"] " or " [:code ":style"] "allowed"]}])

                :opacity          backdrop-opacity
                :z-index          1020
                :pointer-events   "none"}           ;; TODO: trying to prevent change of focus under the bwhen clicking on backdrop (also with the on-click below). Remove!
     :on-click (handler-fn (when backdrop-on-click (backdrop-on-click))
                           (.preventDefault event)
                           (.stopPropagation event))
     }]
   [:div
    {:style (merge {:margin  "auto"                 ;; Child
